Receptacle for monitoring and controlling parallel batteries

ABSTRACT

A receptacle circuit is provided that includes a first circuit path that provides reverse current blocking and reverse polarity protection associated with a positive terminal of a first power source that is connected in parallel with a second power source, a second circuit path that bypasses blocking of the first circuit path, a third circuit path that provides reverse polarity protection associated with a negative terminal of the first power source, and a bypass control circuit that controls the first and second circuit paths based on determination of a predetermined condition.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 62/187,769 filed Jul. 1, 2015 which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to electrical circuits, and more particularly to providing power to electrical circuits.

2. Description of Related Art

Electrical devices commonly derive their power by way of a power supply having one or more batteries. Improper installation (e.g., reverse polarity) or malfunction of a lithium battery can result in failure to provide power, damage to the power supply, damage to the electrical device being powered, and/or an explosion or fire.

For example, a power supply that includes batteries connected in parallel, blocking diodes can be provided to prevent current from flowing in an unwanted direction. However, the blocking diodes can cause voltage drops that can reduce a resultant supply voltage and reduce service life of the battery.

Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved methods and device for monitoring and controlling power sources. The present disclosure provides a solution for this need when two or more power sources are connected parallel to provide power to an electrical device.

SUMMARY OF THE INVENTION

These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.

In an aspect of the disclosure, a receptacle circuit is provided that includes a first circuit path that provides reverse current blocking and reverse polarity protection associated with a positive terminal of a first power source that is connected in parallel with a second power source, a second circuit path that bypasses blocking of the first circuit path, a third circuit path that provides reverse polarity protection associated with a negative terminal of the first power source, and a bypass control circuit that controls the first and second circuit paths based on determination of a predetermined condition.

In embodiments, the predetermined condition can be related to a status of the second power source. The first path can include the first circuit path includes a first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a body diode of the first transistor, and the second circuit path can include a bypass channel of the first transistor. The third circuit path can include a second transistor to provide reverse polarity protection for output from the negative terminal of the first power source.

The bypass control circuit can include a control transistor that controls the bypass channel, wherein when the bypass channel is turned on, output from the first power source flows through the bypass channel instead of through the body diode, and when the bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the body diode. The bypass control circuit can further include a controller that transmits control signals to the control transistor to control the bypass channel.

In embodiments, the controller can control turning off the bypass channel in response to an indication of installation with proper polarity orientation of the first power source so that the output from the first power source flows through the first circuit path, but not through the second circuit path. The controller can monitor terminal voltages of the first power source in response to detection of installation with proper polarity orientation of the first power source. The controller can control turning on the bypass channel in response to a determination that a differential voltage between the terminal voltages of the first and second power sources is below a predetermined threshold, so that the output from the first power source flows through the second circuit path, but not through the first circuit path. The controller can control turning off the bypass channel upon a determination that the differential voltage is above the predetermined threshold.

In an embodiment, a Schottky diode can be connected in parallel to the first transistor to provide reverse current blocking and reverse polarity protection. The first transistor can be an enhancement-mode P-channel MOSFET and the second transistor can be an enhancement-mode N-channel MOSFET.

In accordance with a further aspect of the disclosure, a receptacle circuit can be provided that includes a first circuit path that provides reverse current blocking and reverse polarity protection associated with positive terminals of respective first and second power sources that are connected in parallel relative to one another, a second circuit path that bypasses blocking of the first circuit path, a third circuit path that provides reverse polarity protection associated with negative terminals of the first and second power sources, and a bypass control circuit that controls the first and second circuit paths based on determination of a predetermined condition.

In embodiments, the first path can include at least one first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a first body diode of the first transistor, and at least one second transistor to provide reverse polarity protection for output from the positive terminal of the second power source by a second body diode of the second transistor, and the second circuit path can include a first bypass channel of the first transistor, and a second bypass channel of the second transistor. The third circuit path can include a second transistor to provide reverse polarity protection for output from the negative terminal of the first power source and a third transistor to provide reverse polarity protection for output form the negative terminal of the second power source.

The bypass control circuit can include a first control transistor that controls the first bypass channel, wherein when the first bypass channel is turned on, output from the first power source flows through the first bypass channel instead of through the first body diode, and when the first bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the first body diode, and a second control transistor that controls the second bypass channel, wherein when the second bypass channel is turned on, output from the second power source flows through the second bypass channel instead of through the second body diode, and when the second bypass channel is turned off, output from the second power source undergoes reverse current blocking and reverse polarity protection by the second body diode.

In further embodiments, the bypass control circuit can further include a controller that transmits control signals to the first and second control transistors to control the first and second bypass channels independently of one another.

In accordance with a further aspect of the disclosure, a method of protecting a receptacle circuit includes providing reverse current blocking and reverse polarity protection associated with a positive terminal of a first power source that is connected in parallel with a second power source in a first circuit path, bypassing current blocking of the first circuit path in a second circuit path, providing reverse polarity protection associated with a negative terminal of the first power source in a third circuit path, and controlling the first and second circuit paths based on determination of a predetermined condition associated with the second power source.

In embodiments, controlling the first and second circuit paths can include controlling the bypass channel, wherein when the bypass channel is turned on, output from the first power source flows through a bypass channel of a transistor instead of through a body diode of the transistor, and when the bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the body diode.

The method can further include controlling turning off the bypass channel in response to detection of installation with proper polarity orientation of the first power source, so that the output from the first power source flows through the first circuit path, but not through the second circuit path.

In further embodiments, the method includes monitoring a status of the second power sources in response to detection of installation with proper polarity orientation of the first power source. The method can include controlling the bypass channel based on the status of the second power source.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:

FIG. 1 is a block diagram of an exemplary embodiment of a receptacle circuit configured in accordance with the present disclosure, showing a load and control circuit operatively connected to first and second batteries in accordance with the present disclosure;

FIG. 2 is a schematic diagram of a the receptacle circuit shown in FIG. 1 having a single protection module;

FIG. 3 is a schematic diagram of the receptacle circuit shown in FIG. 1, showing the control circuit in greater detail; and

FIG. 4 is a schematic diagram of another embodiment of the receptacle circuit shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, FIG. 1 shows an embodiment of a power supply receptacle circuit 100 that provides a connection in parallel for two or more power sources. The receptacle circuit further includes a blocking circuit to block reverse polarity or misbalanced voltages, and a bypass circuit to bypass the protection circuitry.

FIG. 1 includes a block diagram of the receptacle circuit 100 that includes a first protection module 102, a second protection module 104, and a bypass control circuit 106. The first and second protection modules 102 are operatively connected in parallel between ground and a power node. 310 (see FIG. 3). The first protection module 102 is configured to couple to positive and negative terminals of a first power source 108, and the second protection module 104 is configured to couple to positive and negative terminals of a second power source 110, with power sources 108 and 110 being coupled in parallel.

The power sources 108, 110 are each a component that supplies DC power to an electric load. The power source can generate power, convert one type of electrical power to another, or convert a different form of energy, such as solar, mechanical, or chemical, into electrical energy. For example, either of the power sources 108, 110 can be a battery that converts chemical energy into electrical power, such as a lithium battery; a photovoltaic (e.g., solar) cell that converts light into an electric current using the photovoltaic effect; or a switched-mode power supply, which converts AC current to DC voltage.

The power sources 108 and 110 can be different types of power sources, or same types. The power sources 108, 110 can be configured to provide power to the same electrical load or to different electrical loads. Additionally, the power sources 108, 110 can output power at the same time or at different times. In one example, one of the power sources 108, 110 can function as a backup for the other power source 108, 110.

The receptacle circuit 100 is not limited to first and second protection modules 102, 104. In embodiments, the receptacle circuit 100 can include additional modules that are configured to couple to at least one additional power sources, wherein the power sources 108, 110, and the additional power source(s) are coupled in parallel to one another. In another embodiment, shown in FIG. 2, the receptacle circuit 100 includes a single module 102, wherein two or more receptacle circuits 100 are provided, and each receptacle circuit is coupled to a respective power source, and the respective power sources are coupled in parallel. In an embodiment, the one or more power sources coupled to the receptacle circuit 100 (e.g., power sources 108, 110, and/or additional power sources) can be coupled in parallel to other power sources.

The receptacle circuit 100 can include a housing (not shown) in which at least a portion of the circuit (e.g., modules 102, 104, 106, and signal lines 120, 122, 132, 134, 136, 138) can be housed. The housing of the receptacle circuit 100 can also include a structure to replaceably mount and secure one or more power sources 108, 110 to the receptacle circuit 100. The housing can support and/or encase the receptacle circuit 100 and/or the one or more power sources 108, 110.

Reverse polarity protection is provided for voltage output by the power sources 108, 110 in a first circuit path of the receptacle circuit 100, which provides reverse polarity protection and current blocking when the power sources 108, 110 are installed improperly, e.g., with reverse polarity, or that the first and second power sources 102, 104 have misbalanced voltages. A bypass control circuit 106 controls a second circuit path of the receptacle circuit 100 based on determination of a predetermined condition. The bypass control circuit 106 can be connected between ground and the power node 310. In an embodiment, the bypass control circuit 106 can be powered by receiving power from the power node 310.

The first protection module 102 further includes first and second polarity protection (PP) devices 112, 114 that protect from reverse polarity, wherein the first PP device 112 further blocks charging of power source 108. The second protection module 104 further includes third and fourth PP devices 116, 118 that protect from reverse polarity, wherein the third PP device 116 further blocks charging of power source 108. The PP devices 112, 114, 116, 118 can be connected in series with the respective battery terminals 124, 126, 128, 130.

In an embodiment, the first and third PP devices 112, 116 are enhancement-mode P-Channel MOSFETs that include a body diode that provides reverse polarity protection and current blocking, including isolating the positive bus supply 122 from the negative polarity, and the second and fourth PP device 114, 118 are enhancement-mode N-Channel MOSFETs that include body diodes that provide reverse polarity protection, including isolating the negative bus supply 120 from positive polarity. The isolation of the negative and positive bus supplies 120, 122 can be simultaneous.

The receptacle circuit 100 further includes the positive supply bus 120 that is coupled to a positive terminal 124 of the first power source 108, a positive terminal 128 of the second power source 110, and the bypass control circuit 106. In addition, the receptacle circuit 100 further includes the negative supply bus 122 that is coupled to a negative terminal 126 of the first power source 108, a negative terminal 130 of the second power source 110, and the bypass control circuit 106.

The bypass control circuit 106 can include or access (e.g., receive voltage measurements from) a voltage monitor 140 that monitors the first and second protection modules 102, 104 via respective monitor lines 132, 134. Additionally, the bypass control circuit 106 can transmit a control signal to the first and second protection modules 102, 104 via respective control lines 136, 138. A control signal can control bypass channels associated with the PP devices 112 and 116. When the control signal turns off the bypass channels associated with the corresponding protection module 102, 104, reverse polarity protection is and current blocking is turned on for the corresponding power source 108, 110, and output from the corresponding power source 108, 110 undergoes reverse current blocking and reverse polarity protection by the body diode of the corresponding PP devices 112, 114, 116, 118. When the control signal turns on the bypass channels associated with the corresponding protection modules 102, 104, reverse polarity protection is turned off for the corresponding power source 108, 110, and output from the corresponding power source 108, 110 flows through the bypass channel of the corresponding PP device 112, 116 instead of through the body diodes of the corresponding PP devices 112, 114, 116, and 118.

With reference to FIGS. 2 and 3, FIG. 2 shows a schematic illustration of the receptacle circuit 100 including protection module 102 with a control transistor 302 of the bypass control circuit 106. Receptacle circuit 100 can include one or more protection modules. FIG. 2 shows an embodiment of receptacle circuit 100 having a single protection module 102, and FIG. 3 shows an embodiment of receptacle circuit 100 having two protection modules 102, 104.

The first and second PP devices 112, 114 are shown as transistors. Output from the positive terminal 104 of the first power source 108 flows through the first PP device 112 to the positive supply bus 122. Output from the negative terminal 106 of the first power source 108 flows through the second PP device 114 to the negative supply bus 120.

The first PP device 112 includes a bypass channel. The first PP device 112 includes a bypass channel. The bypass channel can be formed in the enhancement-mode P-channel MOSFET PP devices 112 and/or 116 by positively biasing a source terminal respect to its gate of the PP device 112, 116, which causes a drain-source channel of the PP device 112, 116 to be turned on.

When the bypass channel is turned on, output from the first power source 108 undergoes polarity protection by the first PP device 112 such that current output by the power source 108 can only flow through the PP device 112 in a selected direction. If the polarity of the voltage is reversed, the current is blocked and cannot flow through the PP device 112. However, when the polarity of the voltage is proper, current output by power source 108 can flow through the PP device 112.

The bypass channel can be formed in the N-channel MOSFET PP devices 114 and/or 118 by positively biasing a gate with respect to its source of the PP device 114, 118, which causes a drain-source channel of the PP device 114, 118 to be turned on.

The bypass control circuit 106 outputs a control signal via control line 136 that is received by control transistor 302. Based on the control signal, the control transistor 302 controls the bypass channel of the PP devices 112, 114.

FIG. 3 shows a schematic illustration of the receptacle circuit 100 having parallel first and second batteries 108, 110 of first and second protection modules 102, 104. First and second PP devices 112, 114 are operatively coupled to the first power source 108 for providing polarity protection. The third and fourth PP devices 116, 118 are operatively coupled to the second power source 110 for providing polarity protection. The first, second, third, and fourth PP devices 112, 114, 116, 118 are shown as transistors. In an embodiment, the first, second, third, and fourth PP devices 112, 114, 116, 118 are enhancement-mode P-channel MOSFETs. In an embodiment, the receptacle circuit 100 could be reconfigured to use relay devices, such as electromechanical or solid-state relay devices, instead of one or more of PP devices 112, 114, 116, 118.

Output from the positive terminal 124 of the first power source 108 flows through the first PP device 112 to the positive supply bus 122. Output from the negative terminal 126 of the first power source 108 flows through the second PP device 114 to the negative supply bus 120. Similarly, output from the positive terminal 128 of the second power source 110 flows through the third PP device 116 to the positive supply bus 122. Output from the negative terminal 130 of the second battery 110 flows through the fourth PP device 118 to the negative supply bus 120.

The structure and function of protection module 102, including the first and second PP devices 112, 114, the first power source 108, and the control transistor 302, are described above with respect to FIG. 2.

With respect to protection module 104, the third PP device 116 also includes a bypass channel. When the bypass channel is turned on, output from the second power source 110 undergoes polarity protection by the third PP device 116 such that current output by the second power source 110 can only flow through the third PP device 116 in a selected direction. If the polarity of the voltage is reversed, the current is blocked and cannot flow through the third PP device 116. However, when the polarity of the voltage is proper, current output by second power source 110 can flow through the third PP device 116. The respective control transistors 302, 304 control the bypass channel of the first and third PP devices 112 and 116 to turn the bypass channels on or off.

The receptacle circuit 100 as shown in FIG. 3 further includes a control transistor 30 that controls the bypass channel of the third PP device 116 to turn the bypass channel on or off. When the bypass channel is turned on, output from the second power source 110 undergoes polarity protection by the third PP device 116 such that current output by the power source 110 can only flow through the third PP device 116 in a selected direction. If the polarity of the voltage is reversed, the current is blocked and cannot flow through the third PP device 116. However, when the polarity of the voltage is proper, current output by the second power source 110 can flow through the third PP device 116. In an embodiment, the control transistors 302 and 304 are enhancement-mode P-channel MOSFETs. In other embodiments, the control transistors 302 and 304 can be In an embodiment, the receptacle circuit 100 could be reconfigured to use relay devices, such as electromechanical or solid-state relay devices, instead of one or more of the control transistors 302, 304.

The receptacle circuit 100, as shown in FIGS. 2 and 3, further includes a controller 306 that optionally receives monitoring signals 132 and 134 and transmits control signals via control lines 136, 138 to the control transistors 302 and 304 to control the bypass channels of the first PP device 112 and the second PP device 116. The controller 306 can be, for example, a processing device, a microcontroller, a field programmable gate array, an application specific integrated circuit, logic circuitry, or the like. In addition, the functions performed by the controller 306 can be performed using software, hardware, firmware, or a combination thereof. The receptacle circuit 100 can further include a Schottky diode 308 coupled in parallel to the first and/or third PP devices 112, 116 to provide polarity protection. An output signal 310 is provided to a load. In embodiments, the receptacle circuit 100 can include resistors 312 to provide circuit functionality as needed. The receptacle circuit 100 can further include pins 314 and 316 for coupling to battery terminals 126 and 124.

In an embodiment, monitoring signal 132 can monitor a signal line that is coupled between the positive terminal 124 of the first power source 108 and the first PP device 112, and monitoring signal 134 can monitor a signal line that is coupled between the positive terminal 128 of the second power source 110 and the third PP device 116 of the second protection module 104.

In an embodiment, the control signal transmitted via control line 136 is transmitted to the first control transistor 302 and the control signal transmitted via control line 138 is transmitted to the second control transistor 304. The controller 306 can control the first and second control transistors 302 and 304 independently of one another in response to the control signals transmitted via control lines 136 and 138.

In an embodiment, the controller 306 turns off the first and second bypass channels in response to detection of a condition. An example of a first condition is an indication that the receptacle circuit 100 is initially turned on, such as based on detection of installation of either of the first and second batteries 108, 110 with proper polarity orientation. An example of a second condition is an indication that voltage of one of the negative of positive supply buses 120, 122 has dropped, such as to a level at which the bypass control circuit 106 is unable to properly manage the bypass channels. When the bypass channel of the first PP devices 112, 116 is turned off, the output from the respective first and second batteries 108, 110 are subjected to diode blocking. When the condition is not detected, the bypass channel is turned on so that the output from the first and second batteries 108, 110 are not subjected to diode blocking. Accordingly, by selectively bypassing diode blocking, voltage drops can be reduced, which can improve the resultant supply voltage and the battery service life.

For example, the monitor signals 132 and 134 can indicate an occurrence of the first condition. The monitor signal 132 monitors the terminal voltage of the first power source 108 and can indicate when the first power source 108 is installed with proper polarity orientation. Similarly, the monitor signal 134 monitors the terminal voltage of the second power source 110 and can indicate when the second power source 110 is installed with proper polarity orientation. In response to an indication of an occurrence of the first condition with respect to the first and/or second power source 108, 110, the controller 306 can turn off the bypass channel of first and/or second PP device 112, 116 for a predetermined time interval that defines the power up phase of either of the first and second batteries 108, 110.

The monitor signals can also indicate an occurrence of the second condition. The controller 306 can determine whether a differential voltage associated with the terminal voltages of the first and second batteries 108, 110 is above a predetermined threshold. The differential voltage refers to a difference between the voltages, e.g., the difference between the terminal voltages of the first and second batteries 108, 110. In response to an indication of an occurrence of the second condition associated with the first and/or second power source 108, 110, the controller 306 can turn off the bypass channel of the first and/or second PP device 112, 116, e.g., to block adverse interaction between power sources, such as charge/discharge currents between batteries.

In embodiments, the controller 306 can respond to a variety of conditions for outputting control signals via control lines 136, 138 to control the first and second bypass channels. The conditions can be external to the receptacle circuit 100. In an example scenario, the receptacle circuit 100 includes a single protection module 102. The power source 108 that is coupled to the receptacle circuit 100 is designated as a backup power source for a second power source that is external to the receptacle circuit 100. The condition to which the controller responds for outputting the control signals via control line 136 is associated with the second power source, such as failure of the second power source.

In one example, when either power source 108 or 110 is installed (for embodiments with one or two protection modules 102, 104) the corresponding bypass channel can be turned off in response to detection of installation with proper polarity orientation. Thus, when the first power source is installed, the output from the corresponding power source undergoes polarity protection by the first PP device 112 and does not flow through the bypass channel of the first PP device 112.

Once proper installation is detected, with proper polarity orientation, the controller 306 can monitor a status of the second power source, such as by receiving information about the status of the second power source. The controller 306 can control the bypass channel of the first PP device 112 based on the status of the second power source.

When the Schottky diodes 308 are not included in the receptacle circuit 100, bodies of the first and third PP devices 112, 116 can be used as blocking diodes. When the Schottky diodes 308 are connected in parallel with body diodes enhancement-mode P-channel MOSFETs, such as PP devices 112 and 116, the Schottky diodes 308 provide a path with a lower forward voltage drop. For example, body diodes typically drop 0.7V, whereas a Schottky diode typically drops 0.3V.

In operation, the controller 306 determines, based on monitoring signals 132, 134, when the first condition has occurred in association with installation, with proper orientation, of either of the first and second batteries 108, 110. In response, the controller 306 turns off the bypass channel associated with the newly installed battery for the predetermined time period, after which the bypass channel is turned on. After the other battery is installed with proper orientation, the controller 306, again turns off the bypass channel associated with the newly installed battery for the predetermined time period, after which the bypass channel is turned on. The controller 306 monitors monitoring signals 132, 134. In response to a determination that the differential voltage associated with the terminal voltages of the first and second batteries 108, 110 exceeds a threshold, the bypass channel is turned off for the battery that has a voltage that is trending in a downward direction with respect to the other battery. The bypass channel can be turned on again if the differential voltage shrinks to a value that is below the threshold.

As shown in FIG. 4, the controller 306 can be external from the receptacle circuit 100 and transmit a control signal via control line 136 to the control transistor 302. The receptacle circuit 100 can include pins for coupling to battery terminals 126 and 124, a pin for coupling to the control line 136 for receiving control signals from the controller 306, and/or pins for coupling to negative and positive bus supplies 120, 122.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for a circuit with superior properties including detecting reverse polarity and measure voltage. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the spirit and scope of the subject disclosure. 

What is claimed is:
 1. A receptacle circuit, comprising: a first circuit path that provides reverse current blocking and reverse polarity protection associated with a positive terminal of a first power source that is connected in parallel with a second power source; a second circuit path that bypasses blocking of the first circuit path; a third circuit path that provides reverse polarity protection associated with a negative terminal of the first power source; and a bypass control circuit that controls the first and second circuit paths based on determination of a predetermined condition.
 2. The receptacle circuit of claim 1, wherein the predetermined condition is related to a status of the second power source.
 3. The receptacle circuit of claim 1, wherein: the first circuit path includes a first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a body diode of the first transistor; the second circuit path includes a bypass channel of the first transistor; and the third circuit path includes a second transistor to provide reverse polarity protection for output from the negative terminal of the first power source.
 4. The receptacle circuit of claim 3, wherein the bypass control circuit includes a control transistor that controls the bypass channel, wherein when the bypass channel is turned on, output from the first power source flows through the bypass channel instead of through the body diode, and when the bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the body diode.
 5. The receptacle circuit of claim 4, wherein the bypass control circuit further includes a controller that transmits control signals to the control transistor to control the bypass channel.
 6. The receptacle circuit of claim 5, wherein the controller controls turning off the bypass channel in response to an indication of installation with proper polarity orientation of the first power source so that the output from the first power source flows through the first circuit path, but not through the second circuit path.
 7. The receptacle circuit of claim 6, wherein the controller monitors terminal voltages of the first power source in response to detection of installation with proper polarity orientation of the first power source.
 8. The receptacle circuit of claim 6, wherein the controller controls turning on the bypass channel in response to a determination that a differential voltage between the terminal voltages of the first and second power sources is below a predetermined threshold, so that the output from the first power source flows through the second circuit path, but not through the first circuit path.
 9. The receptacle circuit of claim 6, wherein the controller controls turning off the bypass channel upon a determination that the differential voltage is above the predetermined threshold.
 10. The receptacle circuit of claim 3, further comprising a Schottky diode connected in parallel to the first transistor to provide reverse current blocking and reverse polarity protection.
 11. The receptacle circuit of claim 3, wherein the first transistor is an enhancement-mode P-channel MOSFET and the second transistor is an enhancement-mode N-channel MOSFET.
 12. A receptacle circuit, comprising: a first circuit path that provides reverse current blocking and reverse polarity protection associated with positive terminals of respective first and second power sources that are connected in parallel relative to one another; a second circuit path that bypasses blocking of the first circuit path; a third circuit path that provides reverse polarity protection associated with negative terminals of the first and second power sources; and a bypass control circuit that controls the first and second circuit paths based on determination of a predetermined condition.
 13. The receptacle circuit of claim 12, wherein: the first circuit path includes at least one first transistor to provide reverse polarity protection for output from the positive terminal of the first power source by a first body diode of the first transistor, and at least one second transistor to provide reverse polarity protection for output from the positive terminal of the second power source by a second body diode of the second transistor, and the second circuit path includes a first bypass channel of the first transistor, and a second bypass channel of the second transistor; and the third circuit path includes a second transistor to provide reverse polarity protection for output from the negative terminal of the first power source and a third transistor to provide reverse polarity protection for output form the negative terminal of the second power source.
 14. The receptacle circuit of claim 13, wherein the bypass control circuit includes: a first control transistor that controls the first bypass channel, wherein when the first bypass channel is turned on, output from the first power source flows through the first bypass channel instead of through the first body diode, and when the first bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the first body diode; a second control transistor that controls the second bypass channel, wherein when the second bypass channel is turned on, output from the second power source flows through the second bypass channel instead of through the second body diode, and when the second bypass channel is turned off, output from the second power source undergoes reverse current blocking and reverse polarity protection by the second body diode.
 15. The receptacle circuit of claim 14, wherein the bypass control circuit further includes a controller that transmits control signals to the first and second control transistors to control the first and second bypass channels independently of one another.
 16. A method of protecting a power supply circuit comprising: providing reverse current blocking and reverse polarity protection associated with a positive terminal of a first power source that is connected in parallel with a second power source in a first circuit path; bypassing current blocking of the first circuit path in a second circuit path; providing reverse polarity protection associated with a negative terminal of the first power source in a third circuit path; and controlling the first and second circuit paths based on determination of a predetermined condition associated with the second power source.
 17. The method of claim 16, wherein controlling the first and second circuit paths includes controlling the bypass channel, wherein when the bypass channel is turned on, output from the first power source flows through a bypass channel of a transistor instead of through a body diode of the transistor, and when the bypass channel is turned off, output from the first power source undergoes reverse current blocking and reverse polarity protection by the body diode.
 18. The method of claim 17 further comprising controlling turning off the bypass channel in response to detection of installation with proper polarity orientation of the first power source, so that the output from the first power source flows through the first circuit path, but not through the second circuit path.
 19. The method of claim 18 further comprising monitoring a status of the second power sources in response to detection of installation with proper polarity orientation of the first power source.
 20. The method of claim 19 further comprising controlling the bypass channel based on the status of the second power source. 